Light emitting diode array containing metamaterial light collimating features and methods for forming the same

Abstract

A light emitting device includes a backplane, first, second and third light emitting diodes located on the backplane, a first patterned metamaterial lens containing first nanostructures located over the first light emitting diode, a second patterned metamaterial lens containing second nanostructures located over the second light emitting diode, and a third patterned metamaterial lens containing third nanostructures located over the light emitting diode. A configuration of the first nanostructures differs from a configuration of the second nanostructures, and a configuration of the third nanostructures differs from the configurations of the first and the second nanostructures.

The invention claimed is: 
     
         1 . A light emitting device, comprising:
 a backplane;   a first light emitting diode, a second light emitting diode, and a third light emitting diode located on the backplane;   a first patterned metamaterial lens comprising first nanostructures located over the first light emitting diode;   a second patterned metamaterial lens comprising second nanostructures located over the second light emitting diode;   a third patterned metamaterial lens comprising third nanostructures located over the third light emitting diode,
 wherein a configuration of the first nanostructures is different from a configuration of the second nanostructures, and a configuration of the third nanostructures is different from the configuration of the first nanostructures and the configuration of the second nanostructures, and 
 wherein the first patterned metamaterial lens, the second patterned metamaterial lens, and the third patterned metamaterial lens comprise a same metamaterial; 
   a transparent conductive material layer between the first patterned metamaterial lens, the second patterned metamaterial lens, and the third patterned metamaterial lens and the first light emitting diode, the second light emitting diode, and the third light emitting diode respectively; and   each of the first light emitting diode, the second light emitting diode, and the third light emitting diode comprising a reflector, the reflector being electrically connected to a doped compound semiconductor portion through an opening in an insulating spacer, the insulating spacer providing electrical isolation between the doped compound semiconductor portion and an active layer of a respective light emitting diode.   
     
     
         2 . The light emitting device of  claim 1 , wherein:
 the configuration of the first nanostructures is different from the configuration of the second nanostructures by at least one of size, spacing or direction; and   the configuration of the third nanostructures is different from the configuration of the first nanostructures and the configuration of the second nanostructures by at least one of size, spacing or direction.   
     
     
         3 . The light emitting device of  claim 2 , wherein:
 the first nanostructures have a different size than the second nanostructures; and the third nanostructures have a different size than the second nanostructures.   
     
     
         4 . The light emitting device of  claim 1 , wherein:
 the first light emitting diode is configured to emit red light;   the second light emitting diode is configured to emit green light;   the third light emitting diode is configured to emit blue light;   the first patterned metamaterial lens is configured to optimize collimation of red light;   the second patterned metamaterial lens is configured to optimize collimation of green light; and   the third patterned metamaterial lens is configured to optimize collimation of blue light.   
     
     
         5 . The light emitting device of  claim 4 , further comprising a dielectric matrix layer laterally surrounding the first light emitting diode, the second light emitting diode, and the third light emitting diode. 
     
     
         6 . The light emitting device of  claim 4 , further comprising: separators surrounding optical cavities, wherein the first light emitting diode, the second light emitting diode and the third light emitting diode are located in respective optical cavities; and wherein the reflectors of the first light emitting diode, the second light emitting diode, and the third light emitting diode are located on sidewalls of the separators. 
     
     
         7 . The light emitting device of  claim 6 , further comprising cavity-fill dielectric material portions located within the optical cavities, and overlying the first light emitting diode, the second light emitting diode, and the third light emitting diode. 
     
     
         8 . The light emitting device of  claim 7 , wherein the transparent conductive material layer overlies a distal surface of the cavity-fill dielectric material portions. 
     
     
         9 . The light emitting device of  claim 4 , wherein each of the first light emitting diode, the second light emitting diode, and the third light emitting diode comprises a vertical stack including a first doped compound semiconductor layer of a first conductivity type, a second doped compound semiconductor layer of a second conductivity type, the second doped compound semiconductor layer comprises the doped compound semiconductor portion, and the active layer configured to emit light at a respective peak wavelength located between the first doped compound semiconductor layer and the second doped compound semiconductor layer. 
     
     
         10 . The light emitting device of  claim 1 , wherein each of the first light emitting diode, the second light emitting diode, and the third light emitting diode is configured to emit incident radiation having a same peak wavelength. 
     
     
         11 . The light emitting device of  claim 10 , wherein the incident radiation comprises ultraviolet radiation or blue light. 
     
     
         12 . The light emitting device of  claim 11 , further comprising:
 a first color conversion medium portion overlying the first light emitting diode, and configured to convert the incident radiation into a first emission light having a first peak wavelength;   a second color conversion medium portion overlying the second light emitting diode, and configured to convert the incident radiation into a second emission light having a second peak wavelength; and   a third color conversion medium portion overlying the third light emitting diode, and configured to convert the incident radiation into a third emission light having a third peak wavelength,   wherein the first peak wavelength, the second peak wavelength, and the third peak wavelength are different from each other.   
     
     
         13 . The light emitting device of  claim 12 , wherein:
 the first patterned metamaterial lens is located above the first light emitting diode;   the second patterned metamaterial lens is located above the second light emitting diode; and   the third patterned metamaterial lens is located above the third light emitting diode.   
     
     
         14 . The light emitting device of  claim 13 , wherein:
 the first emission light comprises red light;   the second emission light comprises green light;   the third emission light comprises blue light;   the first patterned metamaterial lens is configured to optimize collimation of red light;   the second patterned metamaterial lens is configured to optimize collimation of green light; and   the third patterned metamaterial lens is configured to optimize collimation of blue light.   
     
     
         15 . The light emitting device of  claim 12 , wherein each of the first color conversion medium portion, the second color conversion medium portion, and the third color conversion medium portion comprises quantum dots. 
     
     
         16 . The light emitting device of  claim 1 , wherein the light emitting device comprises a display device. 
     
     
         17 . The light emitting device of  claim 16 , wherein:
 the first light emitting diode and the first patterned metamaterial lens are located in a first subpixel of a pixel of the display device;   the second light emitting diode and the second patterned metamaterial lens are located in a second subpixel of the pixel of the display device; and   the third light emitting diode and the third patterned metamaterial lens are located in a third subpixel of the pixel of the display device.   
     
     
         18 . The light emitting device of  claim 16 , wherein the display device comprises a heads up display device. 
     
     
         19 . The light emitting device of  claim 16 , wherein the display device comprises a virtual reality display device. 
     
     
         20 . The light emitting device of  claim 16 , wherein the display device comprises an artificial reality display device.